The height (in meters) of a shot cannonball follows a trajectory given by
$h(t) = -4.9t^2 + 14t - 0.4$
at time t (in seconds). As an improper fraction, for how long is the cannonball above a height of 6 meters?
h(t) = 6
6 = -4.9t^2 + 14t-.4
0 = -4.9t^2 + 14t- 6.4 use quadratic formula to find t = 4/7 to 16/7 sec time between it is higher than 6